Network-initiated area event triggered positioning method for roaming terminal in mobile communication system

ABSTRACT

A network-initiated area event triggered positioning method for a terminal in a session-based position information system is discussed. Network-initiation of area-based positioning of a roaming terminal is discriminated according to a proxy mode and a non-proxy mode, and area-based positioning for the roaming terminal is performed in various manners according to whether an SLP for performing the positioning procedure with respect to the discriminated modes is a V-SLP or an H-SLP.

This application is a Continuation Application of co-pending U.S.application Ser. No. 11/783,202 filed Apr. 6, 2007 and for whichpriority is claimed under 35 U.S.C. §120, which claims priority to U.S.Provisional Application Nos. 60/789,609; 60/795,184; 60/810,631 and60/836,938 filed on Apr. 6, 2006; Apr. 27, 2006; Jun. 5, 2006 and Aug.11, 2006; respectively and Korean Patent Application No. 10-2007-0011578filed on Feb. 5, 2007 in Republic of Korea respectively. The entirecontents of these applications are herein fully incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mobile communication system and, moreparticularly, to a network-initiated area event triggered positioningmethod for a roaming terminal in a session-based position informationsystem.

2. Description of the Related Art

In a mobile communication system a function part for calculating aposition of a terminal is included in a mobile communication network toprovide a location service for transferring a location of a terminal toa certain entity periodically or according to a user request. A networkstructure related to the location service varies depending on aninternal network structure such as 3GPP or 3GPP2, etc.

Methods for calculating the position of the terminal in the mobilecommunication system include a cell-ID method in which an id of a cellto which the terminal belongs is transferred, a method in which timetaken for radiowaves to arrive at each base station from the terminal ismeasured and then the position of the terminal is calculated by usingtriangulation, and a method using GPS.

In order to provide the location service to a user by using the positioncalculating methods, considerable signaling and position informationshould be transferred between the mobile terminal and a position server.Thus, recently, standardized positioning technologies for providing thelocation service, namely, the location services based on the position ofthe mobile terminal, are widely adopted. The positioning technologiescan be provided through a user plane and a control plane, and the SUPL(Secure User Plane Location) that provides the location service throughthe user plane is a typical example of the technologies.

The SUPL, which is effective for transferring position informationrequired for calculating the position of the mobile terminal, transfersposition assistance information such as GPS assistance and uses a userplane data bearer in order to transport positioning technology-relatedprotocols between the mobile terminal and the network.

In general, in the position information system, a locationservice-related SUPL network includes a SUPL agent, an SLP (SUPLLocation Platform) and an SET (SUPL Enabled Terminal). The SUPL agentindicates a logical service access point that uses actually measuredposition information, and the SLP indicates an SUPL service access pointof the network that accesses network resources to obtain positioninformation.

The SET is a device that communicates with the SUPL network using theSUPL interface, which can be, for example, a UE (User Equipment) of aUMTS, an MS (Mobile Station) of GSM, an IS-95 MS, or a laptop computeror a PDA having the SET function. The SET can be also various othertypes of mobile terminals that are connected through a WLAN.

The SET supports procedures defined in the SUPL by interworking with thenetwork through the user plane bearer. In this case, the network towhich the user had initially registered may be called a home network,and the network of an area where the user moves into from the homenetwork area may be called a visited network. An SLP of the home networkmay be called an H-SLP (Home-SLP) and an SLP of the visited network maybe called a V-SLP (Visited-SLP). When the SUPL procedure starts in thenetwork, an SLP to which an external client is first connected may becalled an R-SLP (Requesting SLP). The R-SLP can be a logical entitywhich is the same as the H-SLP or not. The SET for current positioningcan be defined as the target SET.

The SLP, a network element, includes an SPC (SUPL Positioning Center)that calculates an actual location and an SLC (SUPL Location Center)that performs other roles of the SLP that calculates the positioninformation, namely, roaming and resource management, etc. Thus, the SETmay calculate the position information through communication with theSPC via the SLC (proxy mode) or calculate the position information bybeing immediately connected with the SPC (non-proxy mode).

However, although the related art provides the immediate positioningmethod based on the SUPL, it fails to propose area-based, area-relatedor area event triggered positioning for the SUPL-based roaming terminal.

SUMMARY OF THE INVENTION

Therefore, in order to address the above matters the various featuresdescribed herein have been conceived. One aspect of the exemplaryembodiments is to provide a network-initiated area event triggeredpositioning method for a roaming terminal based on an SUPL capable ofallowing a roaming terminal to be positioned effectively in variousmanners.

This specification provides a network-initiated area event triggeredpositioning method for a roaming terminal in a mobile communicationsystem that may include: sending, by a first server, a sessioninitiation message for initiating a trigger session to the roamingterminal; receiving a session start message from the roaming terminal;requesting area ids related to area-based (area-related or areaevent-triggered) positioning from a second server and obtaining areaids; sending a session response message including at least a triggerparameter to the roaming terminal; receiving a positioning initiationmessage from the roaming terminal and transferring it to the secondserver; receiving a calculated position value of the roaming terminalfrom the second server and transferring the received position value tothe roaming terminal; and providing the calculated position valuereceived from the roaming terminal to an agent.

The first server may send the area ids obtained from the second serverto the roaming terminal through the session response message. The firstsever can be an H-SLP and the second server can be a V-SLP.

This specification also provides a network-initiated area eventtriggered positioning method for a roaming terminal in a mobilecommunication system that may include: sending, by a first server, asession initiation message for initiating a trigger session to theroaming terminal; receiving a session start message from the roamingterminal; requesting area ids related to area-based (area-related orarea event-triggered) positioning from a second server and obtainingarea ids; sending a session response message including at least atrigger parameter to the roaming terminal; receiving a positioninginitiation message from the roaming terminal; performing, by the firstserver, a positioning procedure with the roaming terminal and sending acalculated position value of the roaming terminal to the roamingterminal; and providing the calculated position value received from theroaming terminal to an agent.

The first server may send the area ids obtained from the second serverto the roaming terminal through the session response message.

This specification also provides a network-initiated area eventtriggered positioning method for a roaming terminal in a mobilecommunication system that may include: receiving, by the roamingterminal, a session initiation message for initiating a trigger sessionfrom a first server; sending a session start message to the firstserver; receiving a session response message including at least atrigger parameter from the first server; sending a positioninginitiation message to the first server; receiving a measured positionvalue with respect to the roaming terminal from the first server;comparing the received measured position value and a position valueincluded in the trigger parameter to check whether an area event triggercondition is met; and sending, by the roaming terminal, the measuredposition value to the first server when the area event trigger conditionis met.

The roaming terminal may receive area ids related to area-basedpositioning from the first server through the session response message.

This specification also provides a network-initiated area eventtriggered positioning method for a roaming terminal in a mobilecommunication system that may include: sending, by a first server, asession initiation message for initiating a trigger session to theroaming terminal; receiving a session start message including parametersrelated to setting at least a security session from the roamingterminal; requesting, by the first server, area ids related toarea-based (area-related or area event-triggered) positioning from athird server via a second server and obtaining area ids; sending asession response message including at least a trigger parameter and theaddress of the third server to the roaming terminal; receiving acalculated position value with respect to the roaming terminal from theroaming terminal and providing the position value to an agent.

The first server may send the obtained area ids to the roaming terminalthrough the session response message. The first sever can be an H-SLC,the second server can be a V-SLC, and the third server can be a V-SPC.

This specification also provides a network-initiated area eventtriggered positioning method for a roaming terminal in a mobilecommunication system that may include: sending, by a first server, asession initiation message for initiating a trigger session to theroaming terminal; receiving a session start message including parametersrelated to setting at least a security session from the roamingterminal; requesting, by the first server, area ids related toarea-based (area-related or area event-triggered) positioning from asecond server and obtaining area ids; sending, by the first server, asession response message including at least a trigger parameter and theaddress of the third server to the roaming terminal; and receiving acalculated position value with respect to the roaming terminal from theroaming terminal and providing the position value to an agent.

The first server may send the obtained area ids to the roaming terminalthrough the session response message. The first sever can be an H-SLC,the second server can be a V-SLC, and the third server can be an H-SPC.

This specification also provides a network-initiated area eventtriggered positioning method for a roaming terminal in a mobilecommunication system that may include: receiving, by the roamingterminal, a session initiation message for initiating a trigger sessionfrom a first server; sending a session start message includingparameters related to at least a security session to the first server;receiving a session response message including at least a triggerparameter and the address of a second server from the first server;sending, by the roaming terminal, a positioning initiation message tothe second server; performing, by the roaming terminal, a positioningprocedure by setting a security session with the second server by usingthe security session-related parameters; receiving a measured positionvalue with respect to the roaming terminal from the second server;comparing, by the roaming terminal, the received measured position valueand a position value included in the trigger parameter to check whetheran area event trigger condition is met; and providing, by the roamingterminal, the measured position value to the first server when the areaevent trigger condition is met.

The roaming terminal may receive area ids related to area-basedpositioning from the first server through the session response message.

The first server may obtain the area ids from the second server via athird server and provide them to the roaming terminal. In this case, thefirst server is an H-SLC, the second server is a V-SPC, and the thirdserver is a V-SLC.

In addition, the first server may obtain the area ids from the thirdserver and provide them to the roaming terminal. In this case, the firstserver is the H-SLC, the second server is an H-SPC, and the third serveris the V-SLC.

According to an embodiment, the present invention provides anetwork-initiated area event triggered positioning method in a mobilecommunication system having a home network and a visited network thatsupport roaming of a SET (SUPL Enabled Terminal), the method comprising:receiving, by a first server from a SUPL Agent, a MLP message includinga MS-id, a client-is, a quality of positioning (QoP) and a TLRR eventparameter; verifying, by the first server, whether the SET is roaming;sending, by the first server to the SET, a SUPL INIT message including asession-id, a trigger type indicator, a positioning method, and a SLPmode; receiving, by the first server, a SUPL TRIGGERED START messagefrom the SET to start an area event trigger session, the SUPL TRIGGEREDSTART message including a session-id, a location identifier (lid), SETcapabilities ; sending, by the first server to a second server, a RLPTSRLRR message that includes the SUPL TRIGGERED START message, the RLPSSRLIR message including area ids corresponding to the areas for thearea event triggered session; receiving, by the first server, a RLPTSRLRA message that includes a SUPL TRIGGERED RESPONSE message; sending,by the first server, the SUPL TRIGGERED RESPONSE message to the SET, theSUPL TRIGGERED RESPONSE message including a session-id, a positioningmethod, an address of the third server, trigger parameters, and the areaids corresponding to the areas for the area event triggered session;receiving, by a third server, a SUPL POS INIT message from the SET tostart a positioning session with the third server when a current cell-idand one of the area ids correspond to each other, the SUPL POS INITmessage including session-id, lid, and SET capabilities, and wherein thefirst server receives the area ids of the specific area from the secondserver through a third server; performing the positioning session withthe SET by exchanging positioning messages with the SET to obtain apositioning result; sending, by the third server, a SUPL REPORT messageto the SET, the SUPL REPORT message including a session-id and thepositioning result; receiving, by the first server from the SET, a SUPLREPORT message including the session-id and the positioning result; andsending, by the first server to the SUPL Agent, the positioning resultusing an MLP message.

According to an embodiment, the present invention provides anetwork-initiated area event triggered positioning method in a mobilecommunication system having a home network and a visited network thatsupport roaming of a SET (SUPL Enabled Terminal), the method comprising:receiving, from a first server, a SUPL INIT message including asession-id, a trigger type indicator, a positioning method, and a SLPmode; sending, to the first server, a SUPL TRIGGERED START message tostart an area event trigger session, the SUPL TRIGGERED START messageincluding a session-id, a location identifier (lid), SET capabilities;receiving, from the first server, the SUPL TRIGGERED RESPONSE messageincluding a session-id, a positioning method, a V-SPC address, triggerparameters, and the area ids corresponding to the areas for the areaevent triggered session; sending, to a second server, a SUPL POS INITmessage to start a positioning session with the second server when acurrent cell-id and one of the area ids correspond to each other, theSUPL POS INIT message including session-id, lid, and SET capabilities;performing the positioning session with the second server by exchangingpositioning messages with the second server to obtain a positioningresult; receiving, from the second server, a SUPL REPORT messageincluding a session-id and the positioning result; comparing thepositioning result with the specific area in the trigger parameter tocheck if a event trigger condition has been met; sending, to the firstserver, a SUPL REPORT message if the event trigger condition has beenmet, the SUPL REPORT message including a session-id and the positioningresult; and receiving, from the first server, a SUPL END message.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a network-initiated area event triggered positioning methodaccording to a first exemplary embodiment of the present invention;

FIG. 2 is a network-initiated area event triggered positioning methodaccording to a second exemplary embodiment of the present invention;

FIG. 3 is a network-initiated area event triggered positioning methodaccording to a third exemplary embodiment of the present invention; and

FIG. 4 is a network-initiated area event triggered positioning methodaccording to a fourth exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments of the present invention will now be described indetail.

The present invention is implemented in an SUPL network, and withoutbeing limited thereto, the present invention can be also applicable toany wireless communication system that may be operated according to adifferent specification.

In the present invention, in a session-based position informationsystem, when a server and a terminal manage positioning-related triggerinformation, an area event triggered positioning procedure with respectto a terminal which has roamed to a visited network (in case where theterminal moves into a particular position, continuously exists in aparticular area, or moves out of the particular area) is provided.

In the area event triggered positioning, a home network requests areaid(s) set for the area-based positioning from the visited network,obtains area id(s), and provides the obtained area id(s) to the roamingterminal (namely, a target SET).

In the area-based (area-related or area event-triggered) positioning,the roaming terminal is not continuously positioned but it is firstchecked whether the roaming terminal has approached a particular area(requested area or an event area), and when the roaming terminal hasapproached the particular area, the roaming terminal positioningprocedure starts. The roaming terminal determines whether to start ornot the positioning procedure according to whether a positioning startcondition is met or not. The positioning start condition being met meansthat the roaming terminal is near (or has approached) an area (e.g., aparticular area, a requested area, or an event area) that is specifiedin the area event trigger condition information.

When the calculated actual position of the roaming terminal is in anarea specified in the area event trigger condition information (namely,when the area event trigger condition is met), the roaming terminaldetermines that the area event has occurred and sends the calculatedposition value to a client (terminal or an agent included in a network).

Here, the occurrence of the area event refers to the confirmation as towhether the terminal has moved into the particular area, moves out ofthe area, or exists in the area.

In general, the positioning service provided in the SUPL-based positioninformation system is classified into a network-initiated case and aSET-initiated case.

In addition, the SUPL-based positioning service is discriminated in aproxy mode in which the H-SLP of the home network is operated as a proxyso the positioning procedure is performed between the position serverand a roaming SET necessarily through the H-SLP, and a non-proxy mode inwhich the H-SLP is operated in a non-proxy mode so the positioningprocedure is performed directly between the position server and theroaming SET without going through the H-SLP. Here, the position servercan be the H-SLP or the V-SLP.

Types of services can be divided (classified) according to whether theH-SLP (or H-SPC) or the V-SLP (or the V-SPC) performs the positioningfunction for calculating the position of the roaming SET, when thenetwork initiates a service.

In the present disclosure, for the case where the network initiates aservice, four exemplary embodiments will be described according towhether or not the proxy mode is used and the position server being anSLP of which particular network.

First, network-initiated area event triggered positioning method for theroaming terminal according to a first exemplary embodiment of thepresent invention will now be described.

FIG. 1 is a network-initiated area event triggered positioning methodaccording to the first exemplary embodiment of the present invention,showing a roaming case, a network-initiated case, a V-SLP positioningcase and the proxy mode. Namely, the SET (namely, target SET) is theroaming SET which has roamed to the visited network to which the V-SLPbelongs, the V-SLP performs the positioning function (namely, the V-SLPis operated as the position server), and the H-SLP uses the proxy mode.

As shown in FIG. 1, when an area-based positioning is requested from anexternal LCS (Location Services) client, the SUPL agent sends an MLP(Mobile Location Protocol) TLRR (Triggered Location Reporting Request)message to the H-SLP in order to request an area-based positioningservice (area event trigger service) (step S10).

The MLP TLRR message includes parameters such as ms-id, client-id, QoPand tlrr_event, etc. The ms-id indicates a target SET, and the client-idindicates an id of the SUPL agent. The QoP indicates precision degree ofpositioning (temporal delay and spatial precision). The tlrr_event is apositioning related trigger parameter and can be various informationregarding positioning related condition information such as achange_area type of area-based positioning (whether the roaming terminalmoves into a particular area, moves out of the particular area, or islocated in the particular area, etc.), the particular area (the name ofthe particular area or precise position value), and the like.

When there are several types of positioning values or when there areseveral requests for positions, the MLP TLRR message may include aparameter, or the like, for setting priority with respect to eachrequest for positions.

Upon receiving the MLP TLRR, the H-SLP authenticates the SUPL agent andchecks if the SUPL agent is authorized for the service it requests,based on the client-id.

In addition, the H-SLP may apply a subscriber privacy function to theSUPL agent based on the received ms-id.

The H-SLP verifies that the target SET (referred to as ‘SET’hereinafter) supports SUPL by using a SET look-up table, and alsoverifies that the SET is currently SUPL roaming (step S11).

When the SET supports the SUPL and is currently roaming, the SLP sendsan SUPL INIT message to the SET to start an area event triggered sessionwith the SET (step S12). The SUPL INIT message can be transmittedthrough a WAP (Wireless Application Protocol) Push, an SMS (ShortMessage Service) trigger, an SIP (Session Initiation Protocol) Push, anUDP/IP, etc.

The SUPL INIT message may contain a session-ID, a trigger type indicator(e.g., area event), an SLP mode (proxy/non-proxy mode indicator), and anintended positioning method parameter.

Before performing the step S11, the H-SLP may verify (check) privacy ofthe SET, and in this case, if notification or verification to the targetsubscriber (user) is needed, the H-SLP may also include a notificationparameter (notification element) in the SUPL INIT message.

As the H-SLP sends the SUPL INIT message including the trigger typeindicator, the SET can be aware that the area-based positioning has beencurrently requested through the trigger type parameter included in thereceived SUPL INIT message.

Upon receiving the SUPL INIT message, if the SET is not already attachedor establish a circuit switched data connection with a network, the SETestablishes a data connection with a packet data network (3GPP or 3GPP2)(step S13).

In addition, in order to determine if the H-SLP uses the proxy mode orthe non-proxy mode, the SET checks an SLP mode parameter contained inthe SUPL INIT message. When the SLP mode parameter indicates the proxymode, the SET determines that the H-SLP uses the proxy mode andestablishes a secure IP (Internet Protocol) connection to the H-SLP. Inthis case, the IP connection is established to the SET using the addressof the H-SLP that has been provisioned by the home network.

When the data connection is established, the SET sends a SUPL TRIGGEREDSTART message to the H-SLP operating as the proxy in order to start anarea event triggered session (step S14). The SUPL TRIGGERED STARTmessage contains at least session-ID, lid (location identifier) and SETcapability information. The lid is an identifier of a current positionof the SET and indicates an id of a cell in which the SET is currentlylocated.

When the SUPL TRIGGERED START message is received, the H-SLP determinesthe V-SLP based on the lid included in the SUPL TRIGGERED START message.And then, the H-SLP sends an RLP (Roaming Location Protocol) TSRLRR(Triggered Standard Roaming Location Reporting Request) messageincluding the SUPL TRIGGERRED START message to the V-SLP to inform theV-SLP that the target SET will initiate a SUPL positioning procedure(step S15).

The H-SLP should include area-ids request indicator parameter and atlrr_event parameter which was contained in the MLP TLRR message in thestep S10 (namely, parameters related to the area event trigger such asthe area information requested by the SUPL agent), in the SUPL TRIGGERDSTART message.

By sending the RLP TSRLRR message, the H-SLP requests area ids used forthe area event triggered session from the V-SLP.

Upon receiving the RLP TSRLRR message, the V-SLP determines apositioning method (posmethod) to be used for the area event triggeredsession from the SET capabilities included in the RLP TSRLRR message.And, the V-SLP sends an RLP TSRLRA (Triggered Standard Roaming LocationReporting Answer) message including SUPL TRIGGER RESPONSE messageinformation to the H-SLP in order to inform the H-SLP about itsreadiness for an area event triggered session.

The V-SLP also checks the area ids request indicator included in the RLPTSRLRR message. If area ids are requested by the H-SLP, the V-SLP shouldinclude area ids corresponding to the areas for the area event triggeredsession in the SUPL TRIGGER RESPONSE message and then send an RLP TSRLRAmessage including the SUPL TRIGGER RESPONSE message information (stepS16).

The H-SLP forwards the received SUPL TRIGGER RESOPNSE message includingsession-ID, the positioning method (posmethod) and the triggerparameters (trigger-Params) to the SET.

The trigger parameters indicate trigger condition information related tothe area event trigger for positioning.

For example, the trigger parameter may contain trigger conditioninformation indicating the change_area type of the area event and aparticular area (or an event area). The change_area type of the areaevent (it can be referred to the change_area type related to area-basedpositioning or the change_area type related to area event triggeredpositioning) may indicate whether the roaming terminal is moved into theparticular area, moved out of the particular area, or is located in theparticular area. The particular area may include at least one of thename of an administrative district, the name of an area, and latitudeand longitude of a particular position.

The H-SLP may selectively include the area ids or location identifiers(lids) of the specified area for the area event triggered session in theSUPL TRIGGER RESPONSE message (step S17).

Preferably, the area ids can be information indicating a location areain the actual network such as ids of cells belonging to the arearequired for positioning by the SUPL agent, a mobile country code (MCC),a mobile network code (MNC) or a location area code (LAC), etc., or aprimary scrambling code number. In particular, in case of the WCDMA, thearea ids may correspond to the primary scrambling code number.

And then, H-SLP informs the SUPL agent in an MLP TLRA (TriggeredLocation Reporting Answer) message that the triggered location responserequest has been accepted (step S18).

The H-SLP includes a request id parameter (req_id) of the MLP TLRAmessage to be used as a transaction id for the entire duration of thearea event triggered session.

Thereafter, the SET may release the secure IP connection with the H-SLP.

When the area id (or area ids) is/are received in the SUPL TRIGGERRESPONSE MESSAE, the SET checks whether the positioning session startcondition is met.

For example, whether the positioning session start condition is met ornot can be checked by comparing the current area id of the SET and areaids received from the H-SLP.

Namely, the SET compares the current area id (namely, the ID of the cellin which the SET is currently located) and the received area ids(namely, the received cell ids) to check whether there is the same areaid.

When the change_area type of the area event included in the triggerparameters (trigger_params) indicates that SET moves into the particulararea or in the particular area and at least one of the received area idsis identical to the current area id of the SET, the SET starts thepositioning session. That is, when at least one of the received area idsis identical to the current area id of the SET, the SET determines thatthe positioning session start condition is met.

When the change_area type of the area event indicates that the SET movesout of the particular area and the received area ids and the currentarea id of the SET are not identical, the SET determines that thepositioning session start condition is met.

The comparison of the current area id to the received area ids or thearea event trigger in the SET indicates that a position fix has to beperformed. Namely, the SET verifies its substantial position and checkswhether it has approached to the area requested by the SUPL agent.Accordingly, the position of the SET is not always calculated (tracked0but when the SET is determined to have approached to the requested area,the SET informs that the positioning session should start and theposition server (in this case, the V-SLP) starts to calculate theposition of the SET.

When it is verified that the positioning session start condition is metby comparing the area ids, the SET recognizes that it has currentlyapproached to the requested are and sends an SUPL POS INIT message tothe H-SLP to initiate the positioning session (that may be called aposition calculation session) (step S19). The SUPL POS INIT messagecontains at least session-ID and the current area id of the SET. Here,if the SET is not already attached or establishes a circuit switcheddata connection, it attaches itself to the packet data network and sendsthe SUPL POS INIT message to the H-SLP to start the positioning sessionwith the V-S LP.

The H-SLP serving as the proxy forwards the received SUPL POST INITmessage to the V-SLP performing the positioning function using an RLPSSRP message (step S20).

Upon receiving the RLP SSRP message, if a position value (e.g., the cellid) calculated based on information received in the RLP SSRP message isavailable that meets the required QoP, the V-SLP may directly proceed tostep S22, omitting the step S21. If the calculated position value (cellid) does not meet the required QoP, the V-SLP proceeds to the step S21.Thus, it can be noted that the cell id-based positioning method is notused in the step S21.

The SET and the V-SLP may exchange several successive message forperforming actual positioning through the H-SLP to calculate theposition of the SET (step S21). Preferably, the messages exchangedbetween the V-SLP and the SET contain the session-ID and protocols(RRLP, RRC or TIA-801), etc., to be used for the positioning. The V-SLPcalculates the position estimate based on the positioning measurementsreceived from the SET (SET-assisted mode), or the SET calculates theposition estimate based on assistance obtained from the V-SLP (SET-basedmode). In the first exemplary embodiment as shown in FIG. 1, thecalculation of the position is performed in the SET-assisted mode, theV-SLP sends the calculated position result (posresult) in an SUPL REPORTmessage to the SET via the H-SLP (steps S22 and S23). When thecalculation of the position is performed in the SET-based mode, the SUPLREPORT message is not necessary.

When the position result of the SET is received from the V-SLP via theH-SLP, the SET compares the calculated position estimate and a positionvalue of the particular area (event area) specified in the triggerparameter to check if the area event trigger condition has been met,namely, whether the area event has occurred.

Upon comparison, when the position result of the SET is not identical tothe position value specified in the trigger parameter, the SETdetermines that the area event trigger condition has not been met(namely, the area event has not occurred) (step S24) and proceeds backto the step S19 to send the SUPL POS INIT message again to the V-SLP viathe H-SLP (steps S19 and S20).

If, however, the position estimate of the SET is identical to theposition value specified in the trigger parameter (namely, when the areaevent has occurred) (step S24), the SET sends the SUPL REPORT message tothe H-SLP (step S25). The SUPL REPORT message contains the calculatedposition estimate received from the V-SLP and the session ID.

The H-SLP sends the calculated position estimate of the SET and therequested id (req-id) in an MLP TLREP message to the SUPL agent (stepS26).

When a response to the positioning report requested by the SUPL agent issent, the SET waits for a certain time.

And then, the SET repeats the steps S19 to S26 or the steps S19 toS24depending on if the area event condition is fulfilled or not (step S27).

When the last report of the reports required by the SUPL agent has beensent, the H-SLP sends an SUPL END message to the SET to inform the SETthat the positioning session has been ended. Then, the SET and the V-SLPrelease all the resources related to the positioning session,respectively (step S28).

In the first exemplary embodiment of the present invention asillustrated in FIG. 1, when the network initiates the positioningservice, the V-SLP having the positioning function wants to check(calculate) the area-based position of the roaming SET, the roaming SETand the V-SLP establish the area event triggered session via the H-SLPoperating as the proxy and calculate the area-based position of theroaming SET.

An area-based positioning method according to the second exemplaryembodiment of the present invention will now be described.

FIG. 2 is a network-initiated area event triggered positioning methodaccording to a second exemplary embodiment of the present invention.

In the area-based positioning method according to the second exemplaryembodiment of the present invention, a roaming case, a network-initiatedcase, an H-SLP positioning case and a proxy mode are implemented.Compared with the first exemplary embodiment of the present invention,the H-SLP has the positioning function in the second exemplaryembodiment of the present invention.

In the second exemplary embodiment of the present invention, an areaevent triggered session is established in the same manner as that (stepsS10 to S18) of the first exemplary embodiment of the present inventionshown in FIG. 1 (A-I).

When a positioning session start condition is met, the SET (roaming SET)sends an SUPL POS INIT message containing at least current area id (lid)and a SET id (ms id) to the H-SLP serving as a proxy in order to startthe procedure for calculating the position of the SET itself (J).

The H-SLP serving as the proxy (namely, which uses the proxy mode) sendsthe received current area id (lid) and the SET id (ms id) in an RLPSRLIR message to the V-SLP (K).

The V-SLP translates the current area id (lid) to a position estimateand returns the position estimate to the H-SLP (L).

The H-SLP checks if the returned position estimate satisfies the QoP,and when the returned position estimate satisfies the QoP, the H-SLPsends the returned position estimate in an SUPL REPORT message to theSET without performing the positioning (SUPL POS) procedure (M, N).

If, however, the returned position estimate does not satisfy the QoP,the H-SLP performs the positioning (SUPL POS) procedure to calculate aposition estimate of the SET and send the calculated position estimatein the SUPL REPORT message to the SET (M, N).

Thereafter, the H-SLP checks whether an area event has occurred, andprovides a precise area-based position value of the SET to the SUPLagent according to whether the area event has occurred or not, likewiseas in the first exemplary embodiment of the present invention.

In the second exemplary embodiment of the present invention, when thenetwork initiates the area-based positioning service of the roaming SETwhich has roamed to the V-SLP, the area event triggered session isestablished between the V-SLP and the roaming SET via the H-SLP servingas the proxy, and when the SUPL POS INIT message if sent from theroaming SET as the positioning session start condition is met, the H-SLPcalculates an actual position of the roaming SET.

A network-initiated area event triggered positioning method according toa third exemplary embodiment of the present invention will be described.

FIG. 3 is a network-initiated area event triggered positioning methodaccording to a third exemplary embodiment of the present invention.

In the third exemplary embodiment of the present invention, a roamingcase, a network-initiated case, a V-SLP positioning case and a casewhere the H-SLP uses the non-proxy mode are implemented. The SET (targetSET) is a roaming SET which has roamed to the V-SLP and the V-SLPperforms the positioning function.

The V-SLP includes the V-SPC and the V-SLC, and specifically, the V-SPCperforms the positioning function. The H-SLP includes the H-SLC and theH-SPC. Only the H-SLC is shown in FIG. 3, and the H-SLC uses thenon-proxy mode.

Steps S30 to S33 perform the same process as the steps S10 to S13 inFIG. 1.

In step S32, upon checking an SLP mode value contained in the SUPL INITmessage transmitted from the H-SLC, the roaming SET recognizes that theH-SLC uses the non-proxy mode.

In order to start the area-based event triggered session, the SET sendsan SUPL TRIGGERED START message containing at least a session ID,location id (lid) and SET capabilities to the H-SLC. The SET alsoincludes SET nonce and key-id 2 in the SUPL TRIGGERED START message andsends it for authentication required in the non-proxy mode. The key-id 2corresponds to a key for generating a security key to be used forsetting a security session (PSK-TLS session0 between the V-SPC and theSET (step S34).

The H-SLC determines the V-SLC and sends an RLP TSRLRR message includingthe SUPL TRIGGERED START message to the V-SLC to inform the V-SLC thatthe SET has initiated the SUPL positioning procedure.

In this case, the H-SLC should include an area ids request indicatorparameter and the tlrr_event which has been included in the MLP TLRRmessage in the step S30 (namely, parameters related to the area eventtrigger such as the area information requested by the SUPL agent) in theRLP TSRLRR message (step S35).

Thus, by sending the RLP TSRLRR message, the H-SLC requests the area idsused for the area event triggered session from the V-SLC.

The V-SLC informs the V-SPC about the area event triggered sessionthrough internal communication. The V-SLC generates a key to be used formutual authentication between the V-SPC and the SET by using the key-id2 and the SET nonce, and sends the generated key to the V-SPC throughinternal communication. The V-SPC accepts or refuses the request relatedto the area event triggered session and informs the V-SLC about acorresponding result (step S36).

The V-SLC checks the area ids request indicator transmitted from theH-SLC, and if area ids have been requested by the H-SLC, the V-SLCshould include area ids corresponding to the area for the area eventtriggered session in a SUPL TRIGGERED RESPONSE message.

The V-SLC determines a positioning method (posmethod) to be used for thearea event triggered session according to the SET capabilities receivedin the step S35 and sends an RLP TSRLRA message including the SUPLTRIGGERED RESPONSE message to the H-SLC to inform the H-SLC about itsreadiness for an area event triggered session (step S37).

The H-SLC generates a key (security key: PSK_SPC_Key) to be used formutual authentication between the V-SPC and the SET and sends thegenerated key (security key) to the V-SLC via an AUTH RESP message byusing an RLP SSRP tunnel (step S38).

The V-SLC sends the received key (security key) to the V-SPC throughinternal communication (step S39).

The H-SLC sends the SUPL TRIGGERED RESPONSE message received from theV-SLC to the SET. The SUPL TRIGGERED RESOPNSE message containssession-ID, posmethod, V-SPC address and a trigger parameter(trigger_params). The V-SPC address indicates the address of the V-SPCthat performs the positioning function. The trigger parameter indicatestrigger condition information related to the area event trigger forpositioning.

For example, the trigger parameter may contain trigger conditioninformation indicating the change_area type of the area event and aparticular area. The change_area type of the area event may indicatewhether the roaming terminal is moved into the particular area, movedout of the particular area, or is located in the particular. Theparticular area may include at least one of the name of anadministrative district, the name of an area, and latitude and longitudeof a particular position.

The area ids or location identifiers (lids) of the specified area forthe area event triggered session may be included in the SUPL TRIGGERRESPONSE message.

Preferably, the area ids can be information indicating a location areain the actual network such as ids of cells belonging to the arearequired for positioning by the SUPL agent, a mobile country code (MCC),a mobile network code (MNC) or a location area code (LAC), etc., or aprimary scrambling code number. In particular, in case of the WCDMA, thearea ids may correspond to the primary scrambling code number.

Thereafter, steps S41 to S51 are performed in the almost similar manneras the steps S18 to S28 illustrated in FIG. 1 and only the differencestherebetween will now be described.

In the first exemplary embodiment as shown in FIG. 1, when thepositioning session start condition is met, the SET sends the SUPL POSINIT message to the V-SLP via the H-SLP (steps S19 and S20).Comparatively, in the third exemplary embodiment of the presentinvention as shown in FIG. 3, when the positioning session startcondition is met, the SET directly sends the SUPL POS INIT message tothe V-SPC corresponding to the address of the V-SPC included in the SUPLTRIGGERED RESPONSE message received in step S40.

Accordingly, in step S43, the V-SPC directly opens the positioningsession with the SET without going through the H-SLC.

Meanwhile, in step S21 in FIG. 1, the V-SLP opens the positioningsession with the SET via the proxy H-SLP and sends and receivessuccessive messages for calculating the position via the H-SLP tocalculate the actual position of the SET.

Comparatively, in step S43, the calculated position value of the SET issent from the V-SPC to the SET, and the SET checks if an area event hasoccurred based on the calculated position value of the SET. Namely, theSET compares the calculated position value and the position value of theevent area specified in the trigger parameter to check whether they arethe same.

The SET may report the calculated position value to the H-SLC by sendingthe SUPL REPORT message, or may send again the SUPL POS INIT message tothe V-SPC, according to whether the area event occurs or not.

As mentioned above, in the third exemplary embodiment of the presentinvention as shown in FIG. 3, when the network initiates the positioningservice and the V-SPC having the positioning function wants to check(calculate) area-based position of the roaming SET, the H-SLC obtainsthe area ids specified for the area event triggered session from theV-SLC and provides them to the roaming SET, and the roaming SET and theV-SPC directly set a positioning session therebetween without goingthrough the H-SLP serving as the non-proxy and calculates the area-basedposition of the roaming SET.

A network-initiated area event triggered positioning method according toa fourth exemplary embodiment of the present invention will bedescribed.

FIG. 4 is a network-initiated area event triggered positioning methodaccording to a fourth exemplary embodiment of the present invention. Inthe fourth exemplary embodiment of the present invention, a roamingcase, a network-initiated case, an H-SLP positioning case and a casewhere the H-SLP uses the non-proxy mode are implemented. The SET (targetSET) is a roaming SET which has roamed to a visited network to which theV-SLP belongs, and the H-SLP performs the positioning function.

The V-SLP includes the V-SPC and the V-SLC, and only the V-SLC is shownin FIG. 4.

The H-SLP includes the H-SLC and the H-SPC, and the H-SPC performs thepositioning function and the H-SLC uses the non-proxy mode.

Compared with the third exemplary embodiment of the present invention asshown in FIG. 3, in the fourth exemplary embodiment of the presentinvention, the H-SPC performs the positioning function.

Accordingly, when a positioning service request related to an area eventtriggered session is received, the H-SLC of the H-SLP sends the servicerequest to the H-SPC. The H-SPC accepts or rejects the request andprovides a corresponding result to the H-SLC.

The SET nonce and key id 2 parameters transmitted from the SET to theH-SLC in step S34 in FIG. 3 are used to establish the security sessionbetween the V-SPC that performs the positioning function and the SET,while the SET nonce and key-id 2 parameters transmitted from the SET tothe H-SLC in step S65 in FIG. 4 are used to establish a security sessionbetween the H-SPC and the SET.

In step S65, when the SUPL TRIGGERED START message is sent from the SET,the H-SLC sends an RLP TSRLRR message to the V-SLC to request area idscorresponding to areas for an area event triggered session (step S67).

Then, the V-SLC sends SUPL TRIGGERED RESOPNSE message informationincluding the area ids through an RLP TSRLRA message to the H-SLC (stepS68).

The H-SLC sends the SUPL TRIGGERED RESPONSE message received form theV-SLC to the SET. The SUPL TRIGGERED RESPONSE message contains asession-ID, a posmethod, an H-SPC address and a trigger parameter(trigger params). The H-SPC address indicates the address of the H-SPCthat performs the positioning function, and the trigger parameterindicates trigger condition information related to the area eventtrigger for positioning.

For example, the trigger parameter may contain trigger conditioninformation indicating the chang_area type of the area event and aparticular area. The change_area type of the area event may indicatewhether the roaming terminal is moved into the particular area, movedout of the particular area, or is located in the particular. Theparticular area may include at least one of the name of anadministrative district, the name of an area, and latitude and longitudeof a particular position.

The area ids or location identifiers (lids) of the specified area forthe area event triggered session may be included in the SUPL TRIGGERRESPONSE message.

Preferably, the area ids can be information indicating a location areain the actual network such as ids of cells belonging to the arearequired for positioning by the SUPL agent, a mobile country code (MCC),a mobile network code (MNC) or a location area code (LAC), etc., or aprimary scrambling code number. In particular, in case of the WCDMA, thearea ids may correspond to the primary scrambling code number.

Thereafter, steps S70 to S83 are performed in the almost similar manneras the steps S41 to S51 illustrated in FIG. 3 and only the differencestherebetween will now be described.

In the third exemplary embodiment as shown in FIG. 3, when thepositioning session start condition is met, the SET directly sends theSUPL POS INIT message to the V-SPC (step S42). Comparatively, in thefourth exemplary embodiment of the present invention as shown in FIG. 4,when the positioning session start condition is met, the SET sends theSUPL POS INIT message to the H-SPC corresponding to the address of theH-SPC included in the SUPL TRIGGERED RESPONSE message received in stepS69.

The V-SPC in FIG. 3 converts the current area id (lid) included in thereceived SUPL POS INIT message to a position estimate value.Comparatively, the H-SPC in FIG. 4 is not able to directly convert thecurrent area id (lid) included in the received SUPL POS INIT message toa position estimate value, so the H-SPC obtains the position estimatevalue corresponding to the lid upon requesting it from the V-SLC insteps S72 to S75.

In FIG. 4, the H-SPC selectively performs the procedure for calculatingthe actual position of the SET (namely, the positioning procedure)according to whether the converted position estimate value satisfies theQoP or not (steps S76 and S77). The SET checks whether an area event hasoccurred based on the calculated position value of the SET (step S78)and sends a corresponding message to the H-SLC (step S79).

As stated above, in the fourth exemplary embodiment of the presentinvention as shown in FIG. 4, when the network initiates the positioningservice and the H-SPC having the positioning function wants to check(calculate) area-based position of the roaming SET, the H-SLC obtainsthe area ids specified for the area event triggered session from theV-SLC and provides them to the roaming SET, and the roaming SET and theV-SPC directly set a positioning session therebetween without goingthrough the H-SLP serving as the non-proxy and calculates the area-basedposition of the roaming SET.

As so far described, the network-initiated area event triggeredpositioning method for a roaming terminal in a SUPL-based locationinformation system according to the present invention allows diversepositioning methods to be implemented based on the SUPL.

As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims, and therefore allchanges and modifications that fall within the metes and bounds of theclaims, or equivalents of such metes and bounds are therefore intendedto be embraced by the appended claims.

1. A network-initiated area event triggered positioning method in amobile communication system having a home network and a visited networkthat support roaming of a SET (SUPL Enabled Terminal), the methodcomprising: receiving, by a first server from a SUPL Agent, a MLPmessage including a MS-id, a client-is, a quality of positioning (QoP)and a TLRR event parameter; verifying, by the first server, whether theSET is roaming; sending, by the first server to the SET, a SUPL INITmessage including a session-id, a trigger type indicator, a positioningmethod, and a SLP mode; receiving, by the first server, a SUPL TRIGGEREDSTART message from the SET to start an area event trigger session, theSUPL TRIGGERED START message including a session-id, a locationidentifier (lid), SET capabilities; sending, by the first server to asecond server, a RLP TSRLRR message that includes the SUPL TRIGGEREDSTART message, the RLP SSRLIR message including area ids correspondingto the areas for the area event triggered session; receiving, by thefirst server, a RLP TSRLRA message that includes a SUPL TRIGGEREDRESPONSE message; sending, by the first server, the SUPL TRIGGEREDRESPONSE message to the SET, the SUPL TRIGGERED RESPONSE messageincluding a session-id, a positioning method, an address of the thirdserver, trigger parameters, and the area ids corresponding to the areasfor the area event triggered session; receiving, by a third server, aSUPL POS INIT message from the SET to start a positioning session withthe third server when a current cell-id and one of the area idscorrespond to each other, the SUPL POS INIT message includingsession-id, lid, and SET capabilities, and wherein the first serverreceives the area ids of the specific area from the second serverthrough a third server; performing the positioning session with the SETby exchanging positioning messages with the SET to obtain a positioningresult; sending, by the third server, a SUPL REPORT message to the SET,the SUPL REPORT message including a session-id and the positioningresult; receiving, by the first server from the SET, a SUPL REPORTmessage including the session-id and the positioning result; andsending, by the first server to the SUPL Agent, the positioning resultusing an MLP message.
 2. The method of claim 1, further comprising:sending, by the first server, a MLP TLRA message to the SUPL Agent toindicate that the SUPL triggered response has been accepted.
 3. Themethod of claim 1, wherein the calculating of the positioning result isperformed by the third server if SET-assisted mode or performed by theSET if SET-based mode.
 4. The method of claim 1, wherein the SUPL REPORTmessage is received from the SET if a event trigger condition has beenmet as a result of comparing the positioning result with the specificarea in the trigger parameter.
 5. The method of claim 1, furthercomprising: sending, by the first server to the second server, a SUPLEND message using a RLP message; and sending, by the first server to theSET, the SUPL END message.
 6. The method of claim 1, wherein the TLRRevent parameter comprises at least one of a change-area type andposition values of the specific area related to the area event triggeredpositioning.
 7. The method of claim 1, wherein the trigger typeindicator is an area event.
 8. The method of claim 1, wherein theverifying step is based on routing information.
 9. The method of claim1, wherein the first server is a H-SLC, the second server is a V-SLC,and the third server is a V-SPC.
 10. The method of claim 1, wherein thetrigger parameters include area ids that represent one of ids of cellsthat belong to an event area, mobile country codes (MCC), mobile networkcodes (MNC), location area codes (LAC), and primary scrambling codenumbers.
 11. The method of claim 1, wherein the first server uses aproxy mode, and the third server has a positioning function.
 12. Anetwork-initiated area event triggered positioning method in a mobilecommunication system having a home network and a visited network thatsupport roaming of a SET (SUPL Enabled Terminal), the method comprising:receiving, from a first server, a SUPL INIT message including asession-id, a trigger type indicator, a positioning method, and a SLPmode; sending, to the first server, a SUPL TRIGGERED START message tostart an area event trigger session, the SUPL TRIGGERED START messageincluding a session-id, a location identifier (lid), SET capabilities;receiving, from the first server, the SUPL TRIGGERED RESPONSE messageincluding a session-id, a positioning method, a V-SPC address, triggerparameters, and the area ids corresponding to the areas for the areaevent triggered session; sending, to a second server, a SUPL POS INITmessage to start a positioning session with the second server when acurrent cell-id and one of the area ids correspond to each other, theSUPL POS INIT message including session-id, lid, and SET capabilities;performing the positioning session with the second server by exchangingpositioning messages with the second server to obtain a positioningresult; receiving, from the second server, a SUPL REPORT messageincluding a session-id and the positioning result; comparing thepositioning result with the specific area in the trigger parameter tocheck if a event trigger condition has been met; sending, to the firstserver, a SUPL REPORT message if the event trigger condition has beenmet, the SUPL REPORT message including a session-id and the positioningresult; and receiving, from the first server, a SUPL END message. 13.The method of claim 12, wherein the calculating of the positioningresult is performed by the second server if SET-assisted mode orperformed by the SET if SET-based mode.
 14. The method of claim 12,wherein the trigger type indicator is an area event.
 15. The method ofclaim 12, wherein the first server is a H-SLC and the second server is aV-SPC.
 16. The method of claim 12, wherein the trigger parametersinclude area ids that represent one of ids of cells that belong to anevent area, mobile country codes (MCC), mobile network codes (MNC),location area codes (LAC), and primary scrambling code numbers.
 17. Themethod of claim 12, wherein the first server uses a proxy mode, and thesecond server has a positioning function.